At times, emergency aircraft landings are required where the landing gear or undercarriage is inoperative and retained in a retracted position. This is sometimes referred to as “belly landing.” Such landings cause considerable damage to the aircraft, with attendant dangers for the passengers and crew. These dangers are caused partly by the extensive damage to the aircraft fuselage which occurs as the aircraft contacts the runway, but also due to sparks being produced by the aircraft sliding down the runway. Since gasoline or jet fuel is often spilled in an emergency landing, such sparks present a great hazard to the passengers and crew.
Various devices have been suggested to minimize the risk of emergency landings of this type. For instance, early attempts included tensioning wire or nets which were strung across the runway to receive the aircraft nose section and thereby shortening the landing path. However, such techniques create a great shock or impact upon the aircraft which is likely to cause extensive damage.
Another technique is to apply a carpet of foam to the airport runway. This technique lessens the danger of a fire or explosion, but extensive damage to the aircraft cannot be avoided and such a foam carpet is expensive and can only be used once. After use of the foam, it must be removed by washing down the runway, which causes a shut down in air traffic for a number of hours.
Other devices have been suggested which incorporate a movable bed or base for intercepting and receiving a landing aircraft. The prior art devices have all suffered from various disadvantages. For instance, certain of the prior art devices required specially constructed roller systems or conveyors supplied by a dedicated runway. Other of the devices did not provide a sufficient landing area or means to effectively limit the forward travel of the aircraft upon contact. Also, certain of the prior art devices failed to adequately take into account the problem of sparks being generated upon contact with the aircraft.
For example U.S. Pat. No. 4,653,706 discloses an emergency aircraft landing device which fails to solve the problem in an event that at least one of the aircraft wheels malfunctions and remains open while other wheels do not open. Therefore, it causes the aircraft to land in an imbalance mode. Thus, it causes an imbalance landing which causes the aircraft wings hit the ground.
Yet in another example U.S. Pat. No. 3,567,159 discloses an emergency aircraft landing device which fails to solve the problem of containing the nose of the aircraft. Considering that focal point of plane is between wheels which support the nose of the aircraft and wheels which support the wings of the aircraft. However, in new aircrafts distance between front and back axes (nose wheels and wing wheels) is long.
The present invention solves the problem for those aircrafts which can not activate all or some of their wheels for any reason and failure at the time of landing and prevent any accident at the time of landing. The current system which is in use today is to use foam for minimum safe landing which is sprayed over the run way and minimizes the aircraft friction with the runway so that the aircraft may land over the foam on its under-nose surface. So the aforementioned plans could not attract the confidence of the authorities in this industry and it may be even said that such plans would endanger the passengers life and aircraft itself while weather condition and side winds at the first of the runway which make the aircraft unstable when landing, were not considered in these plans and as the aircraft is placed on the media very close to the ground surface there is the danger that wings and nose are collided with the run way surface while in cases where some wheels are not activated and other are activated, this system can not be operative at all.
For instance in U.S. Pat. No. 706, if the wheel under the nose of wing is activated they would be collided with the surface and the aircraft would be crashed and destroyed. Another point is that in such systems the wing length is not considered, which is 64 meter from each side in 747. Then with the smallest movement of the aircraft, wings would hit the ground with the speed of 230 km/h. In U.S. Pat. No. 3,567,159, in addition to the aforesaid problems no point has been considered for placement of the nose. As the aircraft center of gravity is somewhere between rear and front wheels and the wheel base is very wide up to the point under the nose and these aspects have not been considered in this plan since supposing that the aircraft is landed over the system, nose would hit the runway and is disintegrated. Then the function of such system designed to save the aircraft would be useless and ineffective. For instance in a 747 aircraft, the wheel base is 84 ft (25 m). If the aircraft should be grabbed with this system no point has been calculated for placement of the aircraft center of gravity which is located between front and rear axis, then the aircraft would hit the ground with nose or tail.
We have proposed a plan in which the aircraft is grabbed in a height of 9 meter from the ground level and is placed over the system. In our plan the problem of activated and non-activated wheels has been removed for the pilot to land the aircraft. In our plan the conditions have been calculated in a way that the aircraft would be landed on designed points over the apparatus with no damage and it may be repaired then or may be even loaded on the runway by it with no need to any crane.
Therefore, there is a disadvantage in above patent since it fails to contain the nose of the aircraft which can be so called nose dived.
These and other disadvantages are overcome by the landing device of the present invention, as will be apparent in the written description which follows.